The present invention relates generally to a receptacle for mixing and dispensing two substances, and, more particularly, to such a device for dispensing dosed amounts of pharmaceutical formulations under sterile conditions.
It is well known that problems are often encountered when a liquid (e.g. a solvent) kept in a first sealed container is to be transferred under aseptic conditions into a second sealed container and mixed therein with a second substance in either solid or liquid form. This situation occurs particularly in the pharmaceutical art wherein solutions suitable for intravenous or oral administration are often extemporaneously prepared directly by the user by mixing a liquid solvent with a liquid or solid pharmacologically active agent. Both the solvent and the active agent typically are stored separately in distinct containers up to the moment of mixture prepartion.
Several devices have been disclosed, which are provided with pumping means for carrying out the transfer of a liquid solvent from a first sealed container into a second sealed container under aseptic conditions. Such devices are costly and cumbersome and frequently do not afford satisfactory results.
It has been also proposed to keep one of the containers under partial vacuum. When containers of that type are connected to each other by means of a double-tipped, hollow cannula inserted through the rubber plugs of both containers placed in superimposed relationship, the passage of the liquid solvent occurs from the container at atmospheric pressure into the container under partial vacuum. These arrangements also have proved to be costly and, cumbersome and liable to bacterial contamination.
In efforts to overcome the foregoing drawbacks, there was developed recently a system described in U.S. Pat. No. 4,244,467. Therein disclosed is an apparatus for mixing and dispensing two substances and including a first container, a second container, a plug seated in the neck of the second container and having a recess which is open in the upward and outward direction, and an elongated transfer spout secured in the base of the recess and projecting both inwardly into and outwardly from the second container. The spout is provided with two substantially parallel passages extending therethrough and the passage openings are located at different heights by the provision of bevelled end surfaces on the transfer spout.
A further improvement is described by U.S. Pat. No. 4,346,820. Disclosed in that patent is a combination with a first container containing a first substance in a sealed manner, the first container having a neck defining a discharge opening and being sealable by a stopper. A second container contains a second substance in a sealed manner, the second container having a neck defining a discharge opening. Dimensioned to receive the neck of the first container in a sealed manner is one end of a sleeve, the opposite end thereof receiving the neck of the second container. Intermediate the opposite end is a transversely extending, peripherally continuous septum provided with a centrally positioned opening. Although offering some advantages, the above described devices exhibit significant drawbacks such as being not directly compatible with conventional medical equipment used for intravenous administration.